heinzboehmer's 2002 Topaz 6MT Coupe

[Obioban]

Lol, if I didn't want to get this done ASAP, I would 100% take you up on that. A mold for this would fit in the printer, which would make it even easier to make out of CF.

I'm sure this is what you were referring to, but for others benefit...

I want to start doing this

[bigjae46]

Lol, if I didn't want to get this done ASAP, I would 100% take you up on that. A mold for this would fit in the printer, which would make it even easier to make out of CF.

Yes, a 3D printed mold eliminate the hardest part of making the mold. The only downside is it tends to not be as durable as a composite mold. Only becomes an issue if the plan is to make a LOT of parts.

[bigjae46]

I'm sure this is what you were referring to, but for others benefit...

I want to start doing this

Do it! All of the difficulty with compression molds is making the mold and then the math to calculate resin and carbon weights.

EDIT: Google will tell you the density of carbon is 1.7 to 2.0. Stick to 1.4. Learned the hard way. The worst part about working with carbon trimming and finishing. Minimal post work needed - maybe a razor blade and drilling. You do want to use a carbide drill bit (not carbide tipped) which are about $10 to $20 each bit. Use water or a liquid to contain the dust.

I have about 5 lbs of loose carbon strands. Just pay shipping if anyone needs some.

So no excuses!

[heinzboehmer]

Do it!

+1! Put your new printer to work Obioban

I need to get into this as well. Soon.

[heinzboehmer]

Also fixture is done. Only took 15 hrs to print (!).



As expected, the surface finish on the cuts on the bottom isn't great, since they needed support material:



Again, I'm not going for a flatness record with this, so I'll just clean them up with some high grit sandpaper and it'll be fine.

Assembled (and terribly propped up to show how the cuts are useful):





After holding this piece in my hand, I'm very confident that it'll do great on the mill. It's extraordinarily chunky, I would be very surprised if it fails.

The biggest failure point I can think of are the plastic threads. I added a bunch of wall loops to those areas so they should be fine. Additionally, those are really only there to make sure the strut tower bracket is pressed up against the tops of the posts (i.e. flat), they're not taking much load. Most of that load will be taken by the fasteners threaded in from the bottom into where the stock strut bar studs usually live. I'm definitely not ripping those threads out.

And yes, those are class 12.9 bolts going into 3D printed threads. Gotta make sure the fasteners don't fail!